Cause Of Land Pollution
Looking to understand the cause of land pollution?
Definition of Land Pollution
Land pollution may be understood as the deterioration of the earth’s land surfaces, often directly or indirectly as a result of man’s activities.
You might wonder why the focus on man’s activities. Aren’t there also natural factors for land pollution, such as hurricanes, earthquakes and floods that tear down buildings, trees and leave the land polluted with debris and dead bodies?
Cause of Land Pollution – Man or Nature
Well, natural events like volcanic eruptions and tsunamis can bring about land pollution. When the large amounts of sulfuric acid poured out into the atmosphere during volcanic eruptions are precipitated in acid rain, soil acidification might take place where the acid rain falls on the soil. When tsunamis hit the coastal land, the flush of saline water onto soil can lead to soil salination. Nonetheless, these natural events are by far, few and uncommon.
Some other natural events like soil erosion occur more frequently in nature, but when it comes to the scale of land pollution, man’s impact often greatly outdo that of nature.
And if you think a bit more, you might realize that very often, the land pollution that takes place as a result of natural disasters, is actually exacerbated by the very presence of man-made infrastructure, objects, and chemicals etc.
When natural disasters hit, many of these man-made infrastructure (eg. buildings, roads, sewage systems) break down and litter the streets with debris and even sewage overflow. Man-made objects such as television sets, plastic pails or even rubber toys may pour out of homes and float around in flooded roads. Chemicals from industries may leak out onto the surrounding land or water bodies when the buildings containing these hazardous materials are devastated in the disasters.
It is usually not the natural events per se, but these man-made pollutants, that are the cause of land pollution. And these pollutants will take Man, and Nature, substantial effort and time to clean up.
But take another land that has not “suffered” any of man’s interference. Should natural disasters hit, the land might be littered with tree debris and bodies of animals for a while. But the earth does not have to deal with the loads of synthetic debris like plastic or synthetic chemicals that can persist in the environment for long periods.
So after a while, the dead organic materials would simply be returned to earth as nutrients by the works of decomposers (eg. mushrooms, fungi) and scavengers. Very soon, the earth would be cleaned and nourished, and be ready to flourish again.
That is why you can say that the cause of land pollution is often linked directly, or indirectly, to man’s activities.
The Main Factors For Land Pollution
Industrialization and the exploding human population are two of the main factors for the widespread land pollution the earth is facing today. And these two factors are highly linked.
Industrialization gave rise to higher productivity rates, and allowed for more things (including food) to be produced in the same, or a shorter time. The increase in supply of goods that people need facilitate the growth in the human population, since people have more food to eat, more things to use. But with the increase in population came increased demand for more food and things, and the creation of more waste to be disposed of. As you will read about later, waste disposal by landfills is one of the major causes of land pollution.
To cope with the situation, industries had to look into ways to produce more. More resources from the earth need to be extracted – more metals need to be mined, more oil need to be rigged, more trees need to be cut down – to drive the industries and meet the needs of the people. Research and development in production probably led to the creation of synthetic products, like man-made pesticides and synthetic fertilizers (to help food grow faster), plastic, man-made detergents, etc. These synthetic products, many of which are however highly toxic and polluting to the environment, allow the industries to meet the rising demand of the increasing population. In the process of production, the industries produce large amounts of harmful materials that need to be disposed of.
But that is not the end of the story. To earn more, industries also began creating new “needs” amongst the population, by the introduction of new products coupled with highly effective marketing that these products meet a genuine need. These new “needs” in turn drive demand for more goods. A vicious cycle (that is highly unsustainable) has been created.
Directly or indirectly, industrialization and the rising human population have given rise to many human activities that contribute to the cause of land pollution. Some of the human activities that are a substantial cause of land pollution are discussed in greater detail below.
Main cause of land pollution
Waste dumping at landfills and other sites
The dumping of waste at landfills is often cited as a major cause of land pollution. Landfills are well-known for their pollution. Ask someone if he or she would be willing to stay beside a landfill, if given a choice, and the answer is likely to be “no”.
How exactly a landfill is polluted however, really depends on the composition of waste that goes into it. This composition can vary from landfill to landfill (some landfills have specific regulations on the waste that goes into it), and from time to time (depending on the parties who contribute to the garbage during a particular period).
In turn, what this points to is that the need for landfills (i.e. as a means to dispose of the large volumes of waste that man creates) and the conditions in the landfills (i.e. how polluted they are), are very much driven by man – man’s activities (e.g. industrial processes or energy production activities that generate waste), the guidelines man puts in place (e.g. what must be treated prior to disposal at the landfills) and man’s habits (e.g. living by a buy-and-throw lifestyle). This is an important point that few people think about or realize when they look at the pollution taking place in the landfills.
One of the common cause of land pollution in the landfills is the contamination of landfill soil with toxic and even hazardous substances. These substances may be part of the waste itself (e.g. engine oil), are leeched from the waste (e.g. heavy metals from discarded batteries) or are produced by the waste (e.g. dioxins from plasterboards) after some time in the landfill. These toxic substances greatly reduce the quality of the soil in the landfill. Needless to say, the ability of this soil to support life is significantly affected.
Given the large range of materials that could be disposed of at the landfills, the possible contaminants of soil are numerous. The contaminants could include household waste (that in itself includes a large range of materials from organic to inorganic and toxic), sewage waste (in some cases, the waste may even be inadequately treated or untreated) from treatment plants, chemicals and waste materials from industries or factories, radioactive waste (treated or untreated) from nuclear plants, and oily sludge waste from oil refineries, etc. All these materials are a cause of land pollution in the landfills.
And even though landfills are often designed (using technologies like a bottom liner and a leachate collection system) to contain the contaminants within the landfills, leaks often occur and the contaminants can reach surface and underground water bodies – a form of water pollution. The contaminated water then becomes dangerous to life forms that consume it or come into contact it.
The landfills also pollute the environment in other ways. Landfills are notorious for their production of methane gas, which is a flammable green house gas. This gas is mainly produced by decomposing organic wastes found in the landfills. Landfills are also homes to numerous disease vectors like cockroaches and rats.
Land and other types of pollution do not only affect the landfills. Other pieces of land that have been misused by man for illegal dumping of waste suffer the same fate. The only difference might be the nature of the pollution depending on the type of waste disposed of.
With an exploding human population and urbanization, we can expect to see more and more construction activities taking place to create infrastructures like homes, offices, roads, buildings and factories.
However, construction activities are another significant cause of land pollution.
Firstly, new construction projects often require deforestation (which problems to land pollution are discussed below) – either to free up land for the new building or road, or to extract raw materials for the building project.
In addition, construction projects are also responsible for the creation of large amounts of construction waste, which in turn contribute to the cause of land pollution in the landfills.
One of the main problems with construction waste is the large waste articles like concrete and metal debris. They occupy much land, and when disposed of at landfills, inevitably increase the burden on the landfills that usually already quite filled up. As more and more of such construction waste is generated with never-ending construction projects, more land (often vegetation-filled land) would have to be converted to landfills and be subjected to the type of pollution inherent in landfills (described above).
Some construction wastes like oils and paints are hazardous waste, and when not properly disposed of, could also leach harmful chemicals into the ground – a cause of land pollution. Plasterboards, for example, when disposed of in landfills, release toxic gases such as as hydrogen sulfide under anaerobic conditions.
That is why in recent years, there is an increase emphasis on recycling construction waste, so as to divert a substantial proportion of the waste away from the landfills.
Deforestation and Soil Erosion
Deforestation is another one of man’s activities that is a major cause of land pollution. Deforestation often arise from the need to extract more raw materials (e.g. wood) from the forests for industries, or the need to clear more land for human activities, such as agriculture, urban development or building of industries.
Deforestation often results in soil erosion – a cause of land pollution. Without the roots of plants and trees to hold the soil particles, the particles become more prone to being dislodged by wind and water. The eroded soil loses its nutrients and organic matter, as well as its ability to hold water. As such, soil erosion can render fertile land as no longer suited for agriculture, or even turn originally fertile land into barren deserts.
Deforestation does not only bring about desertification through soil erosion. Changes in the local climate and rainfall patterns brought about by deforestation can also convert vast green lands to deserts. Today, desert areas are expanding and taking over futile land. In Mali, the desert has taken over about 220 miles in as few as 20 years.
Other than causing soil erosion, deforestation has also been linked to floods, which can in turn be seen as another cause of land pollution and water pollution. As Andy Lipkis (president & founder of Tree People) said in the movie, The 11th Hour, a tree can capture about 57,000 gallons of water in a 10 to 12-inch flash flood, “it can grab that much water, prevent it from running off, captures it in that sponge, cleans it, puts it back in the aquifer”. But if we take that one tree away, “you got a flood, you got soil erosion. You’ve lost those 57,000 gallons from the local water supply. Then that water is rushing downstream, hurting people, hurting communities, ultimately polluting the ocean.”
Of course, there are also many other problems with deforestation besides being a cause of land pollution. Deforestation destroys the habitats of numerous species of plants and animals growing in the forests, as well as leaves less vegetation to convert the large amounts of carbon dioxide green house gas humans produce to oxygen. However, these problems would not be discussed here.
Agriculture malpractices are another cause of land pollution.
As the demand for food increases with the growing human population, the pressures for farmers to increase their yields also rise. Soil nutrients are necessary for plant growth and development, so farmers generally use fertilizers to correct soil deficiencies and pesticides to kill unwanted insects, fungi, bacteria or viruses.
However, when farmers adopt maladaptive agricultural practices like the overuse of synthetic fertilizers and pesticides, problems arise. Fertilizers and pesticides can contaminate the soil with impurities and toxins (e.g. dioxin) – a cause of land pollution. This pollution situation is even more prevalent when the farming products are manufactured using non-natural and toxic chemicals. In turn, the overuse of these farming products may lead to the build up of these toxic chemicals in the soil, eventually leading to the poisoning of the very crops that the synthetic pesticides and man-made fertilizers were meant to protect and nourish. And when animals and humans consume these contaminated crops, they too will suffer – from bioaccumulation and bio-magnification of the toxins built up in their bodies over time.
Also, while the aim of using fertilizers and pesticides is to increase crop yield, the excessive use of these farm products can reduce crop yields in the long term. Synthetic pesticides and fertilizers that leave acidic by-products in the soil acidify the soil over time. This acidification process leeches away nutrients in the soil and kills organisms in the soil that are beneficial for plant growth – another cause of land pollution. The crop yield, as well as the nutritional value of the crops harvested from that polluted piece of land, is hence reduced.
Other undesired agricultural practices like intensive plowing and mono-crop agriculture can are also a cause of land pollution – these malpractices often lead to nutrient depletion in the soil and large scale soil erosion.
With increasing demand for goods by the growing population, the demand for raw materials has also increased. Some of these raw materials like metals (e.g. copper), coal and precious stones are extracted from the earth via mining. However, mining activities have large impact on the environment. In particular, it is a big cause of land pollution.
With mining activities, especially surface mining projects, the destruction of existing vegetation becomes inevitable.
The land area, void of vegetation, then becomes very susceptible to soil erosion, which is a cause of land pollution.
The mining and mining-related activities (e.g. road construction) also destabilizes the land structures in the area, exacerbating the frequency at which soil erosion occurs, especially when little or no preventive and control measures are employed.
Mining produces large amount of waste rocks (rocks not containing the desired substance such as coal or copper) that need proper disposal, for otherwise they would bring about environmental problems. According to the Safe Drinking Water Foundation, the Canadian mineral industry produces 650 million tones of mining waste every year. This is a huge amount of waste to be disposed of. At times, the mining waste might not be sent for proper disposal, but is instead piled up and simply abandoned (illegally, and irresponsibly) near the mining sites – a cause of land pollution. The “disposal” site becomes an informal landfill, with its inherent pollution problem (described above). The land can no longer be used for other purposes; the landscape is also damaged.
What is worse is that when the mining waste is exposed to the elements, like rainwater, it often leeches harmful substances, like heavy metals (e.g. arsenic), sulphuric acid or chemicals used in processing ores (e.g. cyanide), into the ground – another cause of land pollution by soil contamination. The leeching can also take place in exposed underground mines. These harmful chemicals can pose serious dangers to the lives of organisms living in the soil, as well as animals and humans living near the contaminated land.
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